On Mon, May 10, 2021 at 03:29:11PM -0400, D. Hugh Redelmeier via talk wrote: > It's hard to find general-purpose computers that can be USB clients, > rather that hosts. This mode is called "gadget". > > You can do this with a Raspberry Pi Zero. > > You can also do it with a Pi 4! > > It turns out that the Pi 4's power connector is also a USB 2.0 port. > To conveniently access it, you can use one of these: > > <https://www.buyapi.ca/product/usb-c-pwr-splitter/> > (There's a different splitter that might be aimed at the Pi Zero) > > Why you cannot do this with other models of Pi: The Broadcom chip has one > USB port. It is fed to a USB hub, and that's exposed on the connectors. > A USB hub cannot provide Gadget ports. > > On the Pi 4, the Broadcom's USB port is connected to the power input, with > no hub in the way. > > | From: Stewart C. Russell via talk <[email protected]> > > | Buyapi (in Nepean) and Canakit are Canadian official > | resellers, so are supposed to get priority on stock. Practically, > | they'll run out like everyone else from time to time. > > If I were making a buyapi order, I'd certainly throw in a splitter. Just > on spec. > > > What prompted me to look at this is the description of the "TinyPilot" KVM > project. > > <https://tinypilotkvm.com/> > <https://www.servethehome.com/tinypilot-voyager-kvm-raspberry-pi-remote/> > > This is a Raspberry Pi 4 + extras that acts as another computer's > Keyboard, Video, an Mouse. It can be accessed via ethernet. Not cheap > enough for me. > > Their magic sauce is software (there is an open source subset), > a splitter for the USB C power-in (like above, but US$35), and an HDMI > capture circuit (AliExpress dongle for less that $20 should work). > > According to STH, the obvious competitor is the Lantronix Spider. > The cheapest, used, on ebay is over $200 and may not have the features I'd > like. > > I actually use 4-port UltraHD KVMs that I got for about $100 (in other > words, $25/computer). They fulfill my needs at a lower cost. Maybe a Pi > Zero solution could cost about that. > > The HDMI capture dongles are diverse and mysterious to me. AliExpress's > descriptions are unreliable. For example, the first item in their list > was emblazoned with "4K" but the specs said 1080p was the max resolution. > Any recommendations? > > - I think FullHD is fine. > > - USB 3.0 might be an advantage: higher bandwidth possible > > - "driverless" would be nice. I think that that means it looks like a > USB video camera the software. > > AliExpress is an adventure. I would not bother if I actually had a > serious or > urgent need.
Pretty sure the beaglebone can do usb gadget mode. In fact I think it has to since I believe that is how it implements the serial console as well as storage and networking if desired. Doing video, not sure. I am pretty sure I once saw an HDMI switch that attached to a raspberry pi to control it, but I can't seem to find it. -- Len Sorensen --- Post to this mailing list [email protected] Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
